In addition to the wet type toner, a dry type toner has been widely used for a developer developing for an electrostatic latent image. When the electrostatic latent image is developed with the dry type toner, toner particles thereof are required to have positive or negative charge according to polarity of the electrostatic latent image to be developed. Accordingly, various kinds of charge controlling agents are studied in order to control charging ability of the toner particles.
For example, a phenol type compound is disclosed in Japanese Unexamined Patent Application, First Publication, No. 63-266462, and a negative charge controlling agent which consists of a chromium containing azo dye is disclosed in Japanese Examined Patent Application, Second Publication, No. 41-20153 and Japanese Examined Patent Publication, Second Publication, No. 43-27596 and the like.
However, although the phenol type compound disclosed in the Japanese Unexamined Patent Application, First Publication, No. 63-266462 provides a certain amount of negative charging ability, the level of the charging amount was insufficient. Furthermore, since the color of the chromium containing azo dye disclosed in the Japanese Examined Patent Publication, Second Publication, No. 41-20153, the Japanese Examined Patent Publication, Second Publication, No. 43-27596 and the like is black, the azo dye provides a bad influence on the hue of a color toner when it is used for the toner. Moreover, the azo dye provides bad influence on the environment, since the azo dye includes chromium.
The present invention was achieved based on the aforementioned circumstances. An object of the present invention is to provide: a negative charge controlling agent, wherein the charge controlling agent can provide sufficient charging ability, and has good electrostatic charge rising property, has good compatibility with a binder resin, and has good dispersibility, and by which hue of toner is not influenced if the charge controlling agent is used in the color toner, and a bad influence is not applied on the environment; and a toner for developing an electrostatic charge image by which a clear image can be obtained.